A propeller is generally used as a propulsor for use in aerial vehicles, ships, or other devices. The propeller generally includes blades and a hub, the blades are mounted on the hub, and at the same time, a driving shaft is connected with the hub. The driving shaft rotates under the action of a motor to drive the blades to rotate together. At present, the hub and the driving shaft are fixedly connected with each other generally through threaded close-fit.
When the hub and a rotary shaft are fixed through the threaded close-fit, a tightening direction of the hub is the same as a rotation direction of the blades during operation, and the blades are in a good connection with the rotary shaft in startup and during operation. However, in the event that the blades suddenly slow down or the acceleration varies significantly, under the action of the acceleration, the hub could easily become loosened and come off the driving shaft. In addition, in the event of great vibration amplitude, the hub could easily become loosened and come off the driving shaft, resulting in a propeller runaway. In addition, after a crash occurs, only by a tool can the propeller be unscrewed.